Texas Water Development Board approves provisional Senate Bill 3 Flash Flood Risk Maps

For immediate release. Contact: Media Relations at 512-463-5129

AUSTIN, TEXAS – (March 3, 2026) – The Texas Water Development Board (TWDB) today approved the identification of areas that have a history of consistent or severe flooding, or are at risk of flash flooding, and may warrant the installation, maintenance, and operation of one or more outdoor warning sirens within the 30 counties affected by Senate Bill 3 (SB 3).

Counties may request revisions to the identified areas based on 1) changed conditions, inaccuracies, or information not available during development of the flash flood risk area maps; or 2) proper justification showing that an outdoor warning siren is not warranted in a particular area based on local knowledge.

To assist communities with assessing the identified flash flood hazard risk areas, the TWDB developed an online mapping tool that is now available on the TWDB website. This online tool will help each county determine whether outdoor warning siren systems are warranted based on TWDB guidance, as well as local knowledge and expertise.

Once the areas identified by the TWDB are finalized with input from local communities, SB 3 requires the appropriate municipality or county to install, maintain, and operate an outdoor warning siren system, including all components essential to the system’s functionality. The TWDB Flash Flood Warning Siren Guide outlines requirements that all systems must meet and includes broader recommendations for effective system design and implementation.

For more information and resources, such as guidance on submitting the required Project Plans, please visit the SB 3 Flood Sirens Program webpage or send an email to flood_sirens_program@twdb.texas.gov for assistance.

The TWDB is the state agency charged with collecting and disseminating water-related data, assisting with regional water and flood planning, and preparing the state water and flood plans. The TWDB administers cost-effective financial assistance programs for the construction of water supply, wastewater treatment, flood mitigation, and agricultural water conservation projects.